The effect of different resistance training protocols equalized by time under tension on the force-position relationship after 10 weeks of training period

ABSTRACT

This study investigated the impact of performing two equalized resistance training (RT) protocols for 10 weeks that differ only by repetition duration and number in the force-position and EMG-position relationship. Participants performed an equalized (36 s of time under tension; 3–4 sets; 3 min between sets; 50–55% of one-repetition maximum; 3× week) RT intervention on the bench press and the only different change between protocols was repetition number (RN; 12 vs.6) or duration (RD; 3 s vs. 6 s). Two experimental groups (RN₁₂RD₃, n = 12; and RN₆RD₆, n = 12) performed the RT, while one group was the control (Control, n = 11). Maximal isometric contractions at 10%, 50% and 90% of total bench press range of motion were performed pre- and post-RT, while electromyography was recorded. It demonstrated an increase in isometric force (+14% to 24%, P < 0.001) shifting up the force-position relationship of the training groups after RT, although no difference was between training groups compared to the Control. Neuromuscular activation from pectoralis major presented an increase after training for both RT groups (+44%; P < 0.001) compared to the Control. However, although not significantly different, triceps brachii also presented an increase depending on the protocol (+25%). In conclusion, 10 weeks of an equalized RT with longer RN and shorter RD (or opposite) similarly increases the ability to produce maximal isometric force during the bench exercise across different angles, while neuromuscular activation of the pectoralis major partially explained the shift-up of the force-position relationship after training.

KEYWORDS:

• Resistance training
• repetition duration
• repetition number
• neuromuscular activation
• force-angle relationship

Acknowledgements

The study was funded by Fundação de Amparo à Pesquisa de Minas Gerais (FAPEMIG), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Conselho Nacional de Pesquisa (CNPQ) and Pró-reitoria de Pesquisa da Universidade Federal de Minas Gerais (PRPq-UFMG).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Fundação de Amparo à Pesquisa do Estado de Minas Gerais [grant number APQ-0189214], Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (2013655848-CAPES), and Pró-reitoria de Pesquisa da Universidade Federal de Minas Gerais (PRPq-UFMG).